Use of Device Therapies for Heart Failure Presenter: Leslie A Saxon, MD, University of Southern California (Los Angeles, California)
Almost all patients with symptomatic heart failure (HF) due to systolic dysfunction cared for at tertiary centers for HF management will be eligible for an implantable cardioverter defibrillator (ICD) or a CRT-D (cardiac resynchronization plus ICD) on the basis of an established or an emerging indication, according to data from a US national registry.
Rationale for CHART
The Centers for Heart Failure and Arrhythmia Research and Therapy (CHART) registry prospectively collects in-depth clinical data in ambulatory patients with symptomatic HF due to systolic dysfunction (left ventricular ejection fraction [LVEF] ≤ 40%) referred to tertiary care centers across the United States with combined specialty programs in HF and electrophysiology. Data collected include hospitalizations and cardiac testing. The comprehensive database will provide demographic information, physiologic parameters, and outcome of HF patients, and it will be used for evaluating current treatment and to prescribe future treatment for patients with HF and arrhythmias. Participant centers in CHART include the University of Southern California (Los Angeles), University of California San Francisco Medical Center, Cleveland Clinic Foundation (Ohio), and University of Alabama (Birmingham).
Patient Data
Data collected since April 2003 have been evaluated to determine the indications for and adoption rate of device-based therapies for the prevention of sudden death and treatment of HF. A total of 248 patients have been enrolled, with the following characteristics:

• 
  Age 55.3±14.0 years
  
• 
  Male, 73%
  
• 
  Ischemic etiology, 37%
  
• 
  LVEF 22 ± 8%
  

An implantable device was present in 113 (45.6%) of enrolled patients. Eleven patients had 2 devices (pacemaker and ICD). Of the 88 patients with devices with ICD capability, only 21 (24%) had a history of ventricular tachycardia or cardiac arrest; the remaining 67 patients (76%) had primary prevention indications for the ICD, and 25 (28%) of the implanted ICDs were also CRT-Ds (Table 1). The nonpaced QRS duration in patients with implantable devices was longer than that in patients without devices (131 ± 34 ms vs 117 ± 32 ms). Of the patients who qualified for a CRT-D, 17/37 (46%) had an ICD only.
Table 1. Patients With a Device

Device	N	Prior Arrest	LVEF < 30% + Ischemic Etiology	LVEF < 35% + NYHA Class II-III	LVEF < 35% + QRS > 120 msec + NYHA Class III-IV
PM only	16	0	4	15	8
CRT only	9	0	2	4	4
ICD only	52	15	17	41	15
Std ICD + Std PM	8	1	3	6	3
CRT-D*	25	5	10	22	6

*One patient listed as CRT-D had a standard ICD and CRT pacemaker installed.
CRT = cardiac resynchronization therapy; CRT-D = cardiac resynchronization therapy + defibrillator; ICD = implantable-cardioverter defibrillator; LVEF = left ventricular ejection fraction; NYHA = New York Heart Association; PM = pacemaker; Std = standard
Of the patients without devices, 48/135 (36%) qualified for an ICD under indications currently approved by the US Food and Drug Administration; the remaining 87/135 (64%) qualified for an ICD under emerging indications (Table 2).
Table 2. Patients Without a Device

N	Prior Arrest	LVEF < 30% + Ischemic Etiology	LVEF < 35% + NYHA Class II-III	LVEF < 35% + QRS > 120 msec+ NYHA Class III-IV
135	6	28*	87	20*

*FDA approved indication
Emerging indication
LVEF = left ventricular ejection fraction; NYHA = New York Heart Association Implications
Nearly half of all patients referred to and cared for at tertiary centers for HF management have an implantable device. The majority of ICDs are placed for primary prevention indications, and one third have CRT capability. There are also a significant number of patients with CRT indications who have a right ventricular ICD and have not been upgraded to a CRT. The largest number of patients without devices fall under the emerging indication category (LVEF < 35% + New York Heart Association Class II-III), as used in the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT).
References

1. 
   Saxon LA, De Marco T, Starling R, et al. Use of device therapies for heart failure. J Cardiac Fail. 2004;10(suppl 4):S70. Abstract 192.
   
2. 
   Bardy GH. The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). Late Breaking Clinical Trials. Presented at the American College of Cardiology 2004 Scientific Sessions; March 7-10, 2004; New Orleans, Louisiana.